McDonald's is the world's largest chain of hamburger fast food restaurants, serving around 68 million customers daily in 119 countries across more than 36,000 outlets.[3][4] Founded in the United States in 1940, the company began as a barbecue restaurant operated by Richard and Maurice McDonald. In 1948, they reorganized their business as a hamburger stand using production line principles. Businessman Ray Kroc joined the company as a franchise agent in 1955.